Health-News Hype: Read Between the Headlines

First, the good news: Americans are living longer than ever, with the average life expectancy up to age 77.9 -- a new record, government researchers reported in April. It looks like watching our weight and keeping active are paying off. But wait: There's bad news, other scientists say. People are fatter than ever -- those government numbers must be wrong.

Welcome to another day of health reporting in the media, with its ups and downs and scares and reassurances that leave us all completely confused about what's good or bad for us. One day, a report that sugary soft drinks are a major cause of diabetes has us swearing them off; the next, a scary news flash says the artificial sweetener in most sugar-free versions causes cancer; and the next, we learn it's safe after all. Should we stick to diet drinks? Go back to regular and load up on calories? And does it even matter? After all, another new study said that being overweight is good for us. Can't scientists make up their minds and just give it to us straight?

Truth is, a lot of research findings make headlines before they're really ready for prime time. "Some studies are terrible and some are good, and it often takes a while before we get the right answer," says Louis Aronne, M.D., director of the comprehensive weight-control clinic at Weill-Cornell Medical Center in New York City. "I don't blame people for being confused. But research is always evolving, and there are twists and turns and dead ends. That's how science works."

In many cases, however, the outlook is actually clearer than the contradictory headlines might convey. A small study may not reflect the big picture; studies that reach different conclusions could be looking at different data; one research method may be more valid than another. These nuances are generally glossed over in stories that play up the unexpected or alarming to grab your attention. So what's a health-conscious woman to believe? To clear up some of the confusion -- and make it easier for you to separate the facts from the fanfare in future headlines -- we asked independent experts to give us the bottom line on five of the latest and hottest health debates.

Better known by the brand names NutraSweet and Equal, aspartame was controversial even before it was approved as an artificial sweetener by the U.S. Food and Drug Administration (FDA) in 1981 -- and the debate over its potential health risks has never completely died down. Most recently, a study by independent researchers in Italy found that rats given aspartame in the lab developed higher rates of tumors, lymphomas, and leukemias. The scientists said their study was more credible than earlier rat research because they followed their 500 subjects through the end of their full, natural lives, giving cancers more time to develop. So while other studies may not have found an aspartame-cancer link, these researchers believe that's because the rats weren't allowed to live long enough to develop the disease. Refuting these findings is a National Institutes of Health (NIH) study of almost half a million older Americans, which found no link between lymphomas, leukemias, or brain cancer in people who consumed aspartame in amounts equivalent to about two cans of diet soda a day.

The bottom line: A human study will tell you more than a rat study, especially when there's a large participant pool. "The huge number of people in the NIH study gives it a lot of validity," says Sara Strom, Ph.D., an associate professor of epidemiology at the University of Texas M.D. Anderson Cancer Center, in Houston. The rat study was also large for an animal study, but rats metabolize food differently than people, so results don't necessarily translate. What's more, some scientists suggest the Italian researchers may have let their rats live too long: The usual practice of euthanizing and autopsying rats before they die natural deaths would have ensured that researchers didn't detect cancers due to old age and not aspartame. None of this stopped the rat researchers from calling for an "urgent" review of aspartame standards -- which was "too strong a conclusion," says Strom. The NIH report, on the other hand, stopped short of making any recommendations. "But they did show that moderate consumption is safe," says Strom. Still eyeing that can of diet soda? Drink up -- the most reliable research says it poses no threat in moderation.

Can Extra Weight Be Healthy?

The headlines:

"Some Extra Heft May Be Helpful, New Study Says" --The New York Times "Fat But Fit? Still at Risk" --Saint Paul Press

What could be more basic than the idea that carrying extra weight is bad for you? Yet a major study from the Centers for Disease Control and Prevention (CDC) last year seemed to turn that conventional wisdom on its head. Researchers found that slightly overweight people outlived those who were obese or underweight. Suddenly it looked as though putting on a few extra pounds makes you healthier than being thin. Public health experts were outraged because the findings seemed to undermine efforts to stanch a national epidemic of obesity, a problem strongly linked with serious health conditions such as diabetes and heart disease. But the study's 30 years' worth of data -- culled from three National Health and Nutrition Examination Surveys, each involving between 9,000 and 15,000 people -- seemed solid.

More recent research from Harvard's Brigham and Women's Hospital seemed to support previous studies. Mining information from another large and well-known initiative, the Harvard Women's Health Study, doctors found that as your weight goes up, so does your risk of cardiovascular disease -- even for people who are overweight but not obese. What's more, at every weight level, being physically active improved your odds of evading cardiovascular disease.

The bottom line: The CDC study looked only at how long overweight people are living -- not how healthy they are. "We're getting a lot better at recognizing conditions like cardiovascular disease earlier," says Aronne. "If you treat it aggressively, patients might not die of it prematurely -- but they'll still have the condition." He also points out that because the CDC used body mass index as a measure -- which is calculated from weight and height -- the study doesn't take fitness into account. "There are overweight people who are very fit," Aronne explains, "and normal-weight people who have too much fat." So while the CDC may be right that being overweight doesn't shorten life span, giving up exercise or putting on extra pounds may mean that those additional years will be ones saddled with illness.

Does dairy speed weight loss?

The headlines:

"Dairy Calcium May Aid Weight Loss and Fat Burn" --Sun-Sentinel"Chug Milk, Shed Pounds? Not So Fast" --New York Times

This debate is one of the most contentious fights in the nutrition field these days. The National Dairy Council (NDC), an industry trade group, has been using its famous "Got milk?" campaign to promote studies (some of them NDC-funded) showing that consuming milk and calcium helps you lose weight. But an advocacy group called the Physicians Committee for Responsible Medicine charges that the research is tainted -- and has sued the NDC and other trade groups for "duping" Americans with false claims. Into the fray came two more studies. Researchers at Purdue University who looked at fat-burning in normal-weight women (but not at the women's weight loss per se) found that those who had three cups of milk or dairy a day burned more fat and calories after a meal than women who consumed less. The other study, from the Mayo Clinic, found that when dieters actually tried to drop pounds by cutting calories, they lost about the same amount of weight regardless of their dairy intake.

The bottom line: Go ahead and get the government-recommended three cups of low-fat or fat-free milk products a day -- they're healthful foods that belong in your diet, says Aronne. But does dairy give you some special fat-burning power? "That's just not clear," he says. He notes that obese people sometimes don't get enough vitamin D and calcium because their diets are poor overall. That makes milk and dairy a good idea if you're trying to lose weight because, ideally, you'll be making better nutrition choices overall: Opting for yogurt over a candy bar never hurt anyone's waistline.

Do antidepressants spur suicide?

The headlines:

"Antidepressants linked to adult suicide attempts" --Kansas City Star"Antidepressants seem to cut suicide risk in teenagers and adults, study shows" --New York Times

First, we heard stories that teens using antidepressants were at higher risk of committing suicide. Then came charges that adults taking popular antidepressants such as Prozac, Paxil, and Zoloft are at higher risk as well -- one recent study published in the British Medical Journal reached that conclusion after reviewing hundreds of clinical trials done by drug manufacturers. The FDA has taken the potential threat seriously enough to issue three public warnings while it does its own review of the data. But researchers at a Seattle health-care system looked at hospital records of more than 65,000 depressed patients (adults and adolescents) and found that the risk of suicide was actually highest in the month before starting an antidepressant regimen. Once treatment began, suicide attempts fell by 60 percent.

The bottom line: Certain populations -- possibly including adolescents and people with bipolar disorders -- may be at higher risk of suicide with treatment than others. "We just don't know yet," says Roy Perlis, M.D., a psychiatrist at Massachusetts General Hospital and assistant professor at Harvard Medical School. That's why clinical drug safety trials like those being reviewed by the FDA are important. But the Seattle study is one of the largest real-world studies conducted on the issue and the first to compare suicide rates before and after treatment. (Earlier clinical trials compared people taking an antidepressant with people taking a placebo pill or some other medication.)

"People often start treatment when they're hitting bottom, so you'd expect to see the greatest risk just before medication begins -- and that's what this study shows," says Perlis. Plus, suicide is rare to begin with, making the size of the Seattle study even more key: A rare event even in a small group can seem disproportionately significant, whereas in a larger group it's easily recognized as uncommon. No matter what, depressed people are at higher risk of suicide and should be carefully monitored, before and after treatment. But if you're depressed, don't let fear of medication keep you from getting help.

Talk about spin: These contradictory headlines are based on the same study. Both news stories reported the research accurately but focused on different aspects of a study with a lot of nuances. Researchers at Johns Hopkins and Georgetown Universities did one big analysis of 18 previous soy studies and on average found a 14 percent dip in breast cancer rates for Caucasian women who ate soy products like tofu and bean curd. That's useful news -- so why the doubts? The 18 studies used wildly inconsistent methods, and some were just plain sloppy. For example, much of the research didn't take into account other factors that can cut breast cancer risk -- like having a normal body mass index.

"Women who eat foods like tofu may eat more healthfully in general," says Marilyn Tseng, Ph.D., associate member in the population science division at Fox Chase Cancer Center in Philadelphia. In other words, their lower risk could have been due to some dietary or lifestyle habit other than eating soy. What's more, the researchers said recommending upping soy intake was premature because some of the studies reviewed suggest that taking high-dose soy supplements may actually increase breast cancer risk.

The bottom line: Eating natural soy in foods such as soy milk and tofu is almost certainly safe and may be good for you beyond cancer prevention. "Soy has also been shown to moderately benefit the cardiovascular system," says Tseng. "I wouldn't think one serving a day is too much -- I've eaten soy all my life." And supplements? "That's where the caveats come in," Tseng says. Though the evidence is weak, one compound in soy called genistein is suspected of making DNA more vulnerable to mutations that might lead to leukemia and possibly breast cancer. "Little research has been done on soy supplements or compounds of soy," says Tseng. "And the biggest risks are likely to be in areas we understand less well." So steer clear of supplements, but feel free to enjoy edamame and soy lattes worry-free.

How to Critique Studies Like a Pro

You won't have the experts at your elbow as you interpret the latest health findings -- so how can you tell which studies are helpful and which are overhyped? By thinking like a scientist yourself. Here's what the experts ask themselves when judging research.

How big was the study? Larger studies tend to be most valid because only by examining sizable groups can researchers distinguish between individual anomalies and larger consistent trends. For example, if you're testing a drug, some people will improve for reasons that have nothing to do with the substance being scrutinized -- like diet or genetics -- and these individuals can skew the results if the study is too small.

Who were the participants? Animal studies give a rough idea of what happens in the body, but results don't always hold true for people. To authoritatively test effects in humans, you need a human study.

Was it controlled? A controlled study divides similar participants (same age and sex, say) into at least two groups that then follow different protocols. One group, for example, might be given a medicine while the other receives a dummy pill. This approach allows researchers to compare the effects of treatment against a neutral standard and protect against the placebo effect -- the tendency for some people to get better just because you tell them they will.

Was it double-blind? Controlled studies are even more valid when neither the participants nor the doctors know who's getting the real treatment or the fake stuff. The reason: In addition to preventing the placebo effect, this setup prevents researchers from unintentionally influencing the participants' response or drawing biased conclusions.

Was it all a memory? Can you remember what vegetables you ate a week ago Tuesday? Neither can most people. That's why retrospective studies -- in which people are asked to recall what they ate or did in the past -- are less reliable than prospective studies, in which participants are monitored in real time.

Did experts review it? The best research will pass muster with other scientists, which is why studies published in reputable medical journals like the Journal of the American Medical Association, the New England Journal of Medicine, and the British Medical Journal, which have panels of peer reviewers, are tops in credibility.

A Part of Hearst Digital Media
Redbook participates in various affiliate marketing programs, which means we may get paid commissions on editorially chosen products purchased through our links to retailer sites.